Interconnect structure, semiconductor structure including interconnect structure and method for forming the same

ABSTRACT

An interconnect structure includes a plurality of first pads, a plurality of second pads, a plurality of first conductive lines in a first layer, a plurality of second conductive lines in a second layer, and a plurality of n th  conductive lines in an n th  layer. The first pads and the second pads respectively are grouped into a first, a second and an n th  group. Each of the first pads in first group is connected to one of the second pads in the first group by one of the first conductive lines. Each of the first pads in the second group is connected to one of the second pads in the second group by one of the second conductive lines. Each of the first pads in the n th  group is connected to one of the second pads in the n th  group by one of the n th  conductive lines.

PRIORITY DATA

This patent claims the benefit of U.S. Provisional Patent Application Ser. No. 62/893,716 filed Aug. 29, 2019, the entire disclosure of which is hereby incorporated by reference.

BACKGROUND

The semiconductor industry has experienced rapid growth due to continuous improvements in the integration density of a variety of electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). Such improvement in integration density allows more components to be integrated into a given area. As the demands for miniaturization, higher speed and greater bandwidth, as well as lower power consumption and latency, have grown recently, there are increasing needs for smaller and more creative packaging techniques of semiconductor dies.

As semiconductor technologies further advance, stacked semiconductor devices, e.g., 3D integrated circuits (3DIC), have emerged as an effective alternative to further reduce the physical size of a semiconductor device. In a stacked semiconductor device, active circuits such as logic, memory, processor circuits and the like are fabricated on different semiconductor wafers. Two or more semiconductor wafers or dies may be installed on top of one another to further reduce the form factor of the semiconductor device. Interconnect structures are therefore needed to provide electrical connections between the semiconductor wafers or dies.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a schematic view illustrating a portion of an interconnect structure according to aspects of the present disclosure.

FIG. 2 is a perspective view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 3 is a perspective view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 4 is a perspective view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 5 is a schematic view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 6 is a schematic view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 7 is a schematic view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 8 is a schematic enlarged view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure.

FIG. 9 is a schematic view illustrating a semiconductor structure according to aspects of the present disclosure.

FIG. 10 is a flowchart of a method for forming a semiconductor structure according to aspects of the present disclosure.

FIGS. 11A to 11F are schematic views illustrating a semiconductor structure at various fabrication stages constructed according to aspects of the present disclosure in one or more embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

This description of illustrative embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present disclosure. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down.” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “attached,” “affixed,” “connected” and “interconnected” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the disclosure are illustrated by reference to the embodiments. Accordingly, the disclosure expressly should not be limited to such embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features, the scope of the disclosure being defined by the claims appended hereto.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in the respective testing measurements. Also, as used herein, the terms “substantially,” “approximately” or “about” generally mean within a value or range that can be contemplated by people having ordinary skill in the art. Alternatively, the terms “substantially,” “approximately” or “about” mean within an acceptable standard error of the mean when considered by one of ordinary skill in the art. People having ordinary skill in the art can understand that the acceptable standard error may vary according to different technologies. Other than in the operating/working examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for quantities of materials, durations of times, temperatures, operating conditions, ratios of amounts, and the likes thereof disclosed herein should be understood as modified in all instances by the terms “substantially.” “approximately” or “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the present disclosure and attached claims are approximations that can vary as desired. At the very least, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Ranges can be expressed herein as being from one endpoint to another endpoint or between two endpoints. All ranges disclosed herein are inclusive of the endpoints, unless specified otherwise.

Other features and processes may also be included. For example, testing structures may be included to aid in the verification testing of the 3D packaging or 3DIC devices. The testing structures may include, for example, test pads formed in a redistribution layer or on a substrate that allows the testing of the 3D packaging or 3DIC, the use of probes and/or probe cards, and the like. The verification testing may be performed on intermediate structures as well as the final structure. Additionally, the structures and methods disclosed herein may be used in conjunction with testing methodologies that incorporate intermediate verification of known good dies to increase the yield and decrease costs.

The term “interconnect structure” refers to a structure providing electrical connection between two workpieces such as two dies, two semiconductor packages, or two sets of terminals over one die/semiconductor package. In some embodiments, the interconnect structure includes a plurality of conductive lines (also referred to as routing resources) and a plurality of vias disposed in a plurality of dielectric layers. In some embodiments, the interconnect structure can be a part of a die, a part of a semiconductor package, a part of a printed circuit board (PCB), a part of an interposer, or the like.

The routing resources of the interconnect structure are horizontal conductive lines serving as main tracks providing the electrical connections. In some embodiments, the routing resources occupy a majority of area in every layer of the interconnect structure, while the vias are used to electrically connect the routing resources in different layers. To electrically connect two dies (two packages or two sets of bonds over one die), the routing sources in different layers may connect one pad disposed over one of the two dies to another pad disposed over the other die through the vias. It is found that such routing design is complicated and utilization of the routing resources is not efficient.

The present disclosure therefore provides an interconnect structure having a simple and more efficient routing design. In some embodiments, the interconnect structure may include two sets of pads: a plurality of first pads and a plurality of second pads, wherein the two sets of pads may be bonded to pads over two dies (also referred to as chips) or two packages. In some embodiments, the two sets of pads may be bonded to pads disposed over a same wafer, a same die or a same package, but separated from each other. In some embodiments, the first pads and the second pads are arranged to form arrays having columns and rows. In some embodiments, the rows formed by the first pads are aligned with the rows formed by the second pads. In some embodiments, the first pads may be grouped into a plurality of groups, such as a first group, a second group and an n^(th) group, arranged in columns. In some embodiments, the second pads may be grouped into a plurality of groups, such as a first group, a second group and an n^(th) group, arranged in columns. In some embodiments, the first pads and the second pads are electrically connected group-by-group. For example, the first pads and the second pads in the same group are electrically connected through conductive lines in a same layer. In some embodiments, the first pads and the second pads in the same group, including those in different rows, are electrically connected through conductive lines in the same layer. In some embodiments, first pads and second pads in separate groups, including those in a same row, are electrically connected through conductive lines in another layer. Accordingly, utilization of the routing resources (the conductive lines) is improved and design for the routing resources is simplified by the provided interconnect structure.

FIG. 1 is a schematic view of a portion of an interconnect structure according to aspects of the present disclosure. In some embodiments, the interconnect structure 100 can include a first region 102 a and a second region 102 b, wherein the first region 102 a and second region 102 b are separated from each other by a spacing region 104. In some embodiments, the interconnect structure 100 can include two sets of pads P1 and P2. For example, the interconnect structure 100 can include a plurality of first pads P1 disposed in the first region 102 a and a plurality of second pads P2 disposed in the second region 102 b. In some embodiments, a quantity of the first pads P1 and a quantity of the second pads P2 are the same, but the disclosure is not limited thereto. As shown in FIG. 1, the first pads P1 are arranged to form a first array A1, and the second pads P2 are arranged to form a second array A2. Each of the first array A1 and the second array A2 has a plurality of rows (i.e., the first row R1, the second row R2, the third row R3 and the m^(th) row Rm) extending along a first direction D1, and a plurality of columns (i.e., the first column C1, the second column C2, the third column C3 and the l^(th) column C1) extending along a second direction D2. In some embodiments, the first direction D1 and the second direction D2 are perpendicular to each other. In some embodiments, m and l respectively are positive integer equal to or greater than 2. In some embodiments, m is equal to l. In some alternative embodiments, m is different from l. In other words, the first array A1 and the second array A2 respectively have rows (i.e., the first row R1, the second row R2, the third row R3 and the m^(th) row Rm) extending along the first direction D1 and parallel to each other along the second direction D2.

In some embodiments, the first pads P1 in the first array A1 are arranged along the first direction D1 to form the first row R1, the second row R2, the third row R3 and the m^(th) row Rm. The first pads P1 in the first array A1 are arranged along the second direction D2 to form the first column C1, the second column C2, the third column C3 and the l^(th) column C1. Similarly, the second pads P2 in the second array A2 are arranged along the first direction D1 to form the first row R1, the second row R2, the third row R3 and the m^(th) row Rm. The second pads P2 in the second array A2 are arranged along the second direction D2 to form the first column C1, the second column C2, the third column C3 and the l^(th) column C1. In some embodiments, the first pads P1 in the first row R1 of the first array A1 are aligned with the second pads P2 in the first row R1 of the second array A2, the first pads P1 in the second row R2 of the first array A1 are aligned with the second pads P2 in the second row R2 of the second array A2, and the first pads P1 in the m^(th) row Rm of the first array A1 are aligned with the second pads P2 in the m^(th) row Rm of the second array A2, as shown in FIG. 1.

The first pads P1 are separated from each other. For example, in each of the rows R1, R2 and Rm of the first array A1, the first pads P1 are separated from each other by a first horizontal distance Dh1 (shown in FIG. 5), and in each of the columns C1, C2 and C1 of the first array A1, the first pads P1 are separated from each other by a first vertical distance Dv1 (shown in FIG. 5). In some embodiments, the first horizontal distance Dh1 and the first vertical distance Dv1 are the same, but the disclosure is not limited thereto. Similarly, the second pads P2 are separated from each other. For example, in each of the rows R1, R2 and Rm of the second array A2, the second pads P2 are separated from each other by a second horizontal distance Dh2 (shown in FIG. 5), and in each of the columns C1, C2 and C1 of the second array A2, the second pads P2 are separated from each other by a second vertical distance Dv2 (shown in FIG. 5). In some embodiments, the second horizontal distance Dh2 and the second vertical distance Dv2 are the same, but the disclosure is not limited thereto. In some embodiments, the first horizontal distance Dh1 and the second horizontal distance Dh2 are the same, and the first vertical distance Dv1 and the second vertical distance Dv2 are the same, but the disclosure is not limited thereto. Further, at least one of the first pads P1, such as the first pad P1 in the l^(th) column C1 of the first array A1, is adjacent to one of the second pads P2, such as the second pad P2 in the first column C1 of the second array A2. The at least one of the first pads P1 is separated from the adjacent second pad P2 by a spacing distance Ds, and the spacing distance Ds is greater than the first horizontal distance Dh1 and the second horizontal distance Dh2, as shown in FIG. 1. In some embodiments, the spacing distance Ds is substantially equal to a width of the spacing region 104, but the disclosure is not limited thereto.

In some embodiments, the first pads P1 are grouped into a first group G1, a second group G2, a third group G3 and an n^(th) group Gn. In some embodiments, n is an integer equal to or greater than 2. As shown in FIG. 1, the first pads P1 in each of the first row R1, the second row R2 and the n^(th) row Rm of the first array A1 are respectively grouped into the first group GI, the second group G2 and the n^(th) group Gn. The first group G1, the second group G2 and the n^(th) group Gn extend along the second direction D2 and are parallel to each other along the first direction D1. In other words, each of the first group G1, the second group G2 and the n^(th) group Gn includes some columns of the first array A1. Further, quantities of the first pads P1 in each of the first group G1, the second group G2 and the n^(th) group Gn are the same. Similarly, the second pads P2 are grouped into a first group G1, a second group G2, a third group G3 and an n^(th) group Gn. As shown in FIG. 1, the second pads P2 in each of the first row R1, the second row R2 and the m^(th) row Rm of the second array A2 are grouped into the first group G1, the second group G2 and the n^(th) group Gn. The first group G1, the second group G2 and the n^(th) group Gn extend along the second direction D2 and are parallel to each other along the first direction D1. In other words, each of the first group G1, the second group G2 and the n^(th) group Gn includes some columns of the second array A2. Further, quantities of the second pads P2 in each of the first group G1, the second group G2 and the n^(th) group Gn are the same.

Referring to FIGS. 2 and 3, the interconnect structure 100 further includes a plurality of first conductive lines disposed in a first layer, a plurality of second conductive lines disposed in a second layer and a plurality of n^(th) conductive lines disposed in an n^(th) layer. The first layer, the second layer and the n^(th) layer are stacked to form a multi-layered structure. In some embodiments, the first layer, the second layer and the n^(th) layer can be dielectric layers. In some embodiments, the conductive lines formed in a lowest dielectric layer can be referred to as a first metallization (M1) layer, the conductive lines formed in the dielectric layer over the M1 layer can be referred to as a second metallization (M2) layer, and the embodiments may utilize one or more other metallization layers, such as a third metallization (M3) layer to an upper most metallization (Mn) layer.

Referring to FIG. 2, in some embodiments, the interconnect structure 100 includes a plurality of first conductive pillars CPI disposed in the first region 102 a and a plurality of second conductive pillar CP2 disposed in the second region 102 b. Each of the first pads P1 is coupled to one of the first conductive pillars CP1, and each of the second pads P2 is coupled to one of the second conductive pillars CP2. Each of the first conductive pillars CPI includes a plurality of vias and a plurality of landing ports. As shown in FIG. 2, the vias and the landing ports are alternately disposed. Each of the second conductive pillars CP2 includes a plurality of vias and a plurality of landing ports. As shown in FIG. 2, the vias and the landing ports are alternately disposed. Details about the vias and the landing ports will be discussed in the following description. The first conductive pillars CP1 and the second conductive pillars CP2 are embedded in and penetrates the first layer, the second layer and the n^(th) layer.

Referring to FIG. 2, in some embodiments, each of the first pads P1 in the first row R1 in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the first group GI of the second array A2 by the first conductive pillar CPI and one of the first conductive lines in the first layer. In some embodiments, the first conductive lines are the uppermost metallization layer Mn. Further, the first conductive line Mn is electrically connected to the first pad P1 through a first via Vn and a first landing port Ln of the first conductive pillar CP1, and electrically connected to the second pad P2 through a first via Vn and a first landing port Ln of the second conductive pillar CP2, as shown in FIG. 2. Each of the first pads P1 in the first row R1 in the second group G2 of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the second group G2 of the second array A2 by one of the second conductive lines in the second layer. In such embodiments, the second layer is disposed under the first layer, and the second conductive lines are the Mn−1 layer. Further, the second conductive line Mn−1 is electrically connected to the first pad P through a first via Vn, a first landing port Ln, a second via Vn−1 and a second landing port Ln−1 of the first conductive pillar CPI, and electrically connected to the second pad P2 through a first via Vn, a first landing port Ln, a second via Vn−1 and a second landing port Ln−1 of the second conductive pillar CP2, as shown in FIG. 2. Each of the first pads P1 in the first row R1 in the n^(th) group Gn of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the n^(th) group Gn of the second array A2 by one of the n^(th) conductive lines in the n^(th) layer. In such embodiments, the n^(th) layer is lowest layer, and the n^(th) conductive lines are the lowest metallization layer M1. Further, the n^(th) conductive line M1 is electrically connected to the first pad P1 through a first via Vn, a first landing port Ln, a second via Vn−1, a second landing port Ln−1, an n^(th) via VI and an n^(th) landing port LI of the first conductive pillar CPI, and electrically connected to the second pad P2 through a first via Vn, a first landing port Ln, a second via Vn−1, a second landing port Ln−1, an n^(th) via V1 and an n^(th) landing port L1 of the second conductive pillar CP2, as shown in FIG. 2. In some embodiments, a quantity of the metallization layers is equal to a quantity of the groups.

It should be noted that each of the first conductive pillars CPI may have a functional portion and a dummy portion, and each of the second conductive pillars CP2 may have a functional portion and a dummy portion. As shown in FIG. 2, because the first conductive line Mn is electrically connected to the first pad P1 through the first via Vn and the first landing port Ln of the first conductive pillar CPI, and electrically connected to the second pad P2 through the first via Vn and the first landing port Ln of the second conductive pillar CP2, the first vias Vn and the first landing ports Ln in the first and second conductive pillars CP and CP2 are referred to as the functional portions. In contrast to the functional portion (i.e. the first vias Vn and the first landing ports Ln), the second via Vn−1, the second landing port Ln−1, the n^(th) via V1, and the n^(th) landing port L1 are referred to as the dummy portion. Similarly, because the second conductive line Mn−1 is electrically connected to the first pad P1 through the first via Vn, the first landing port Ln, the second via Vn−1 and the second landing port Ln−1 of the first conductive pillar CP1, and electrically connected to the second pad P2 through the first via Vn, the first landing port Ln, the second via Vn−1 and the second landing port Ln−1 of the second conductive pillar CP2, the first vias Vn, the first landing ports Ln, the second vias Vn−1 and the second landing ports Ln−1 in the first and second conductive pillars CP1 and CP2 are referred to as the functional portion. In contrast to the functional portion (i.e. the first vias Vn, the first landing ports Ln, the second vias Vn−1 and the second landing ports Ln−1), the third via Vn−2, the third landing port Ln−2, the n^(th) via V, and the n^(th) landing port L1 are referred to as the dummy portion. Referring to the n^(th) conductive line M1, because the n^(th) conductive line M1 is electrically connected to the first pad P through the first via Vn, the first landing port Ln, the second via Vn−1, the second landing port Ln−1, the n^(th) via VI and the n^(th) landing port L1 of the first conductive pillar CP, and electrically connected to the second pad P2 through the first via Vn, the first landing port Ln, the second via Vn−1, the second landing port Ln−1, the n^(th) via V1 and the n^(th) landing port L1 of the second conductive pillar CP2, all of the vias (including the first vias Vn, the second vias Vn−1 and the n^(th) vias V1) and all of the landing ports (including the first landing ports Ln, the second landing ports Ln−1 and the n^(th) landing ports L1) are referred to as the functional portion.

Accordingly, although each of the first conductive pillars CP1 may include a same height, heights of the functional portions of the first conductive pillars CP in different groups G1, G2 and Gn are different from each other, and heights of the functional portions of the second conductive pillars CP2 in different groups GI, G2 and Gn are different from each other. Additionally, heights of the functional portions of the first conductive pillars CPI and height of the functional portion of the second conductive pillars CP2 in the same group are the same.

Referring to FIG. 3, each of the first pads P1 in the second row R2 in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the second row R2 in the first group GI of the second array A2 by one of the first conductive lines Mn in the first layer, and each of the first pads P1 in the m^(th) row Rm in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the m^(th) row Rm in the first group G1 of the second array A1 by the first conductive lines Mn in the first layer. As mentioned above, the interconnect structure 100 further includes the first via Vn, the second via Vn−1 and the nh via V1. It should be noted that in FIG. 3, only the functional portions of the first conductive pillars CP1 and the functional portion of the second conductive pillars CP2 are shown.

According to the different embodiments as shown in FIGS. 2 and 3, it should be noted that the first pads P1 and the second pads P2 are electrically connected group-by-group. The first pads P1 and the second pads P2 in different groups, including those in the same row, are not electrically connected, as shown in FIG. 2. Further, in the same group, the first pads P1 and the second pads P2 are electrically connected row-by-row through the conductive lines in the same layer.

Referring to FIG. 4, in some embodiments, each of the first pads P1 in the first row R1 in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the first group GI of the second array A2 by one of the first conductive lines in the first layer. In some embodiments, the first conductive lines are the lowest metallization layer M1. The first conductive line M1 is electrically connected to the first pad P1 through a first landing port LI, a first via VI, a second landing port L2, a second via V2, an n^(th) landing port Ln and an n^(th) via Vn of the first conductive pillar CP1, and electrically connected to the second pad P2 through a first landing port L1, a first via VI, a second landing port L2, a second via V2, an n^(th) landing port Ln and n^(th) via Vn of the second conductive pillar CP2, as shown in FIG. 4. Each of the first pads P1 in the first row R1 in the second group G2 of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the second group G2 of the second array A2 by one of the second conductive lines in the second layer. In such embodiments, the second layer is disposed over the first layer, and the second conductive lines are the M2 layer. The second conductive line M2 is electrically connected to the first pad P1 through a second landing port L2, a second via V2, an n^(th) landing port Ln and an n^(th) via Vn of the first conductive pillar CP1, and electrically connected to the second pad P2 through a second landing port L2, a second via V2, an n^(th) landing port Ln and n^(th) via Vn of the second conductive pillar CP2, as shown in FIG. 4. Each of the first pads P1 in the first row in the n^(th) group Gn of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the n^(th) group Gn of the second array A2 by one of the n^(th) conductive lines in the n^(th) layer. In such embodiments, the n^(th) layer is upper most layer, and the n^(th) conductive lines are the uppermost metallization layer Mn. The n^(th) conductive line Mn is electrically connected to the first pad P1 through an n^(th) landing port Ln and an n^(th) via Vn of the first conductive pillar CPL and electrically connected to the second pad P2 through an n^(th) landing port Ln and n^(th) via Vn of the second conductive pillar CP2, as shown in FIG. 4. In some embodiments, a quantity of the metallization layers is equal to a quantity of the groups.

As mentioned above, each of the first conductive pillars CPI may have a functional portion and a dummy portion, and each of the second conductive pillars CP2 may have a functional portion and a dummy portion. As shown in FIG. 4, because the first conductive line M1 is electrically connected to the first pad P1 through the first landing port L1, the first via V1, the second landing port L2, the second via V2, the n^(th) via Vn and the n^(th) landing port Ln of the first conductive pillar CP1, and electrically connected to the second pad P2 through the first landing port L1, the first via V1, the second landing port L2, the second via V2, the n^(th) landing port Ln and the n^(th) via Vn of the second conductive pillar CP2, all of the vias (including the first vias V1, the second vias V2 and the n^(th) vias Vn) and all of the landing ports (including the first landing ports L1, the second landing ports L2 and the n^(th) landing ports Ln) are referred to as the functional portion. Similarly, because the second conductive line M2 is electrically connected to the first pad P1 through the second landing port 2, the second via V2, the n^(th) landing port Ln and the n^(th) via Vn of the first conductive pillar CPL, and electrically connected to the second pad P2 through the second landing port L2, the second via V2, the n^(th) landing port Ln and the n^(th) via Vn of the second conductive pillar CP2, the second via V the second landing port L the second land ports L2, the second vias V2, the n^(th) vias Vn and the n^(th) landing ports Ln in the first and second conductive pillars CPI and CP2 are referred to as the functional portion. In contrast to the functional portion, the first vias V1 and the first landing ports L1 are referred to as the dummy portion. Because the n^(th) conductive line Mn is electrically connected to the first pad P through the n^(th) landing port Ln and the n^(th) via Vn of the first conductive pillar CP, and electrically connected to the second pad P2 through the n^(th) lading port Ln and the n^(th) via Vn of the second conductive pillar CP2, the n^(th) vias Vn and the n^(th) landing ports Ln in the first and second conductive pillars CP1 and CP2 are referred to as the functional portion. In contrast to the functional portion (i.e. the n^(th) vias Vn and the n^(th) landing ports Ln), other vias and landing ports of the first and second conductive pillars CPI and CP2 are referred to as dummy portions.

Accordingly, although each of the first conductive pillars CPI may include a same height, heights of the functional portions of the first conductive pillars CP1 in different groups G1, G2 and Gn are different from each other, and heights of the functional portions of the second conductive pillars CP2 in different groups G1, G2 and Gn are different from each other. Additionally, heights of the functional portions of the first conductive pillars CP1 and height of the functional portion of the second conductive pillars CP2 in the same group are the same.

According to the different embodiments as shown in FIGS. 2 and 4, it should be noted that the first pads P1 and the second pads P2 are electrically connected group-by-group. The first pads P1 and the second pads P2 in different groups, including those in the same row, are not electrically connected. In contrast, the electrical connection between the first pads P1 and the second pads P2 in the individual groups are achieved by different conductive lines in different layers.

FIG. 5 is a schematic view of a portion of the interconnect structure according to aspects of the present disclosure. In some embodiments, each of the first pads P1 in the first row R1 in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the first group G1 of the second array A2 by one of the first conductive lines Mn (or M1) in the first layer. Each of the first pads P1 in the second row R2 in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the second row R2 in the first group GI of the second array A2 by one of the first conductive lines Mn (or M1) in the first layer. Each of the first pads P1 in the m^(th) row Rm in the first group G1 of the first array A1 is electrically connected to one of the second pads P2 in the m^(th) row Rm in the first group GI of the second array A2 by one of the first conductive lines Mn (or M1) in the first layer.

Referring to FIG. 6, each of the first pads P1 in the first row R1 in the second group G2 of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the second group G2 of the second array A2 by one of the second conductive lines Mn−1 (or M2) in the second layer. Each of the first pads P1 in the second row R2 in the second group G2 of the first array A1 is electrically connected to one of the second pads P2 in the second row R2 in the second group G2 of the second array A2 by one of the second conductive lines Mn−1 (or M2) in the second layer. Each of the first pads P1 in the m^(th) row Rm in the second group G2 of the first array A1 is electrically connected to one of the second pads P2 in the m^(th) row Rm in the second group G1 of the second array A2 by one of the second conductive lines Mn−1 (or M2) in the second layer.

Similarly, each of the first pads P1 in the first row R1 in the n^(th) group Gn of the first array A1 is electrically connected to one of the second pads P2 in the first row R1 in the n^(th) group Gn of the second array A2 by the n^(th) conductive lines M1 (or Mn) in the n^(th) layer. Each of the first pads P1 in the second row R2 in the n^(th) group Gn of the first array A1 is electrically connected to one of the second pads P2 in the second row R2 in the n^(th) group Gn of the second array A2 by one of the n^(th) conductive lines M1 (or Mn) in the n^(th) layer. Each of the first pads P1 in the m^(th) row Rm in the n^(th) group Gn of the first array A1 is electrically connected to one of the second pads P2 in the m row Rm in the n^(th) group Gn of the second array A2 by one of the n^(th) conductive lines M1 (or Mn) in the n^(th) layer.

According to the embodiment as shown in FIGS. 5 and 6, it should be noted that the first pads P1 and the second pads P2 are electrically connected group-by-group. The first pads P1 and the second pads P2 in the same group, including those in different rows, are electrically connected row-by-row by one of the conductive lines in the same layer. In contrast, the electrical connections between the first pads P1 and the second pads P2 in the individual groups are achieved by different conductive lines in different layers.

As mentioned above, the first pads P1 in adjacent rows are separated from each other by the first vertical distance Dv1, and the second pads P2 in adjacent rows are separated from each other by the second vertical distance Dv2. Further, each of the first conductive lines Mn (or M1) has a width W1, and each of the second conductive lines Mn−1 (or M2) has a width W2. Similarly, each of the n^(th) conductive lines M1 (or Mn) has a width Wn. In some embodiments, the widths W1, W2 and Wn are the same. In some embodiments, a sum of widths W1 of the first conductive lines Mn (or M1) electrically connecting the first pads P1 and the second pads P1 in the same row is less than the first vertical distance Dv1 and the second vertical distance Dv2, as shown in FIG. 5. A sum of widths W2 of the second conductive lines Mn−1 (or M2) electrically connecting the first pads P1 and the second pads P2 in the same row is less than the first vertical distance Dv1 and the second vertical distance Dv2, as shown in FIG. 6. Similarly, a sum of widths Wn of the n^(th) conductive lines M1 (or Mn) electrically connecting the first pads P and the second pads P2 in the same row is less than the first vertical distance Dv1 and the second vertical distance Dv2.

Further, in some embodiments, a sum of widths W1 of the first conductive lines Mn (or M1) electrically connecting the first pads P1 and the second pads P2 in the same row is less than the spacing distance Ds (shown in FIG. 1). A sum of widths W2 of the second conductive lines Mn−1 (or M2) electrically connecting the first pads P1 and the second pads P2 in the same row is less than the spacing distance Ds. Similarly, a sum of widths Wn of the n^(th) conductive lines MI (or Mn) electrically connecting the first pads P1 and the second pads P2 in the same row is less than the spacing distance Ds. In some embodiments, a sum of widths W1, W2 and Wn of all the conductive lines Mn, Mn−1 and M1 (or M1, M2 and Mn) is less than the spacing distance Ds.

Referring to FIGS. 5 and 6, in some embodiments, the first pads P1 in each row of each group includes a first subordinate pad P1/R1-1, a second subordinate pad P1/R1-2, and a e subordinate pad P1/R1-k sequentially arranged along the first direction D1, the second pads P2 in each row of each group include a first subordinate pad P2/R1-1, a second subordinate pad P2/R1-2, and an e subordinate pad P2/R1-k sequentially arranged along the first direction DI. In some embodiments, k is an integer equal to or greater than 2. For example, the first pads P1 in the first row R1 of the first group G1 of the first array A1 include a first subordinate pad P1/R1-1, a second subordinate pad P1/R1-2 and a k^(th) subordinate pad P1/R1-k sequentially arranged along the first direction D1. In some embodiments, the first pads P in the first array A1 can be defined according to Table 1:

TABLE 1 G1 G2 Gn P1/R1-1 P1/R1-2 P1/R1-k P1/R1-1 P1/R1-2 P1/R1-k P1/R1-1 P1/R1-2 P1/R1-k P1/R2-1 P1/R2-2 P1/R2-k P1/R2-1 P1/R2-2 P1/R2-k P1/R2-1 P1/R2-2 P1/R2-k P1/Rm-1 P1/Rm-2 P1/Rm-k P1/Rm-1 P1/Rm-2 P1/Rm-k P1/Rm-1 P1/Rm-2 P1/Rm-k

For example, the second pads P2 in the first row R1 of the first group G1 of the second array A2 are defined to a first subordinate pad P2/R1-1, a second subordinate pad P2/R1-2 and a k subordinate pad P2/R1-k sequentially arranged along the first direction D1. In some embodiments, the second pads P2 in the second array A2 can be defined according to Table 2:

TABLE 2 G1 G2 Gn P2/R1-1 P2/R1-2 P2/R1-k P2/R1-1 P2/R1-2 P2/R1-k P2/R1-1 P2/R1-2 P2/R1-k P2/R2-1 P2/R2-2 P2/R2-k P2/R2-1 P2/R2-2 P2/R2-k P2/R2-1 P2/R2-2 P2/R2-k P2/Rm-1 P2/Rm-2 P2/Rm-k P2/Rm-1 P2/Rm-2 P2/Rm-k P2/Rm-1 P2/Rm-2 P2/Rm-k

In some embodiments, k is not equal to m, for example, k is less than m, but the disclosure is not limited thereto. In some embodiments, k is not equal to n, for example, k is less than n, but the disclosure is not limited thereto. In some embodiments k is not equal to l, for example, k is less than l, but the disclosure is not limited thereto.

In each of the first group G1, the second group G2 and the n^(th) group Gn, the first subordinate pad P1/R1-1 in the first array A1 is electrically connected to the first subordinate pad P2/R1-2 in the second array A2, the second subordinate pad P1/R1-2 in the first array A1 is electrically connected to the second subordinate pad P2/R1-2 in the second array A2, and the k^(th) subordinate pad P1/R1-k in the first array A1 is electrically connected to the k^(th) subordinate pad P2/R1-k in the second array A2.

Please refer to FIG. 7, which is a schematic view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure. In some embodiments, the conductive lines can include patterns having horizontal lines connected to each other by vertical lines, as shown in FIGS. 5 and 6. In other embodiments, the conductive lines can include patterns having horizontal lines connected to each other by slanted lines, as shown in FIG. 7.

FIG. 8 is a schematic enlarged view illustrating a portion of an interconnect structure for a semiconductor structure according to aspects of the present disclosure. In some embodiments, at least one of the first pads P1 includes a subsidiary line SUB1-1 extending along a third direction. The third direction can be different from the first direction D1 and the second direction D2, but the disclosure is not limited thereto. For example, the first pads P1 in the same row, such as, for example but not limited thereto, the first row R1 respectively include the subsidiary line SUB1-1. Similarly, at least one of the second pads P2 includes a subsidiary line SUB2-1 extending along a fourth direction. The fourth direction can be different from the first direction D1 and the second direction D2, but the disclosure is not limited thereto. In some embodiments, the third direction and the fourth direction can be the same, but the disclosure is not limited thereto.

Still referring to FIG. 8, in some embodiments, the first pads P1 in different rows have subsidiary lines extending in different directions. For example, the first pads P1 in the first row R1 respectively include the subsidiary line SUB1-1, the first pads P1 in the second row R2 respectively include the subsidiary line SUB1-2, and the first pads P1 in the m row Rm respectively include the subsidiary line SUB1-m. In some embodiments, extending directions of the subsidiary lines SUB1-1, SUB1-2 and SUB1-m are different from each other, but the disclosure is not limited thereto.

Similarly, in some embodiments, the second pads P2 in different rows have subsidiary lines extending different directions. For example, the second pads P2 in the first row R1 respectively include the subsidiary line SUB2-1, the second pads P2 in the second row R2 respectively include the subsidiary line SUB2-2, and the second pads P2 in the m^(th) row Rm respectively include the subsidiary line SUB2-m. In some embodiments, extending directions of the subsidiary lines SUB2-1, SUB2-2 and SUB2-m are different from each other, but the disclosure is not limited thereto.

In some embodiments, the subsidiary lines SUB1-m and SUB2-m are formed by a pad layer, which is coupled to the pads, but the disclosure is not limited thereto. In some embodiments, the subsidiary lines SUB-m and SUB2-m can be formed to provide extra routing resources. For example, the subsidiary lines SUB1-m and SUB2-m can be coupled to the first vias Vn (or the n^(th) via Vn), as shown in FIG. 8. Because extending directions of the subsidiary lines SUB1-1, SUB1-2 and SUB1-m are different from each other, locations of the first vias Vn or the n^(th) vias Vn may be adjusted such that the first vias Vn or the n^(th) vias Vn can be coupled to the subsidiary lines SUB1-1. SUB1-2 and SUB-m. Consequently, spaces between adjacent pairs of vias Vn arranged in the same column may be different from each other. In some embodiments, the subsidiary lines SUB1-m and SUB2-m provide more places for accommodating the vias. In other words, more vertical connections can be obtained.

Please refer to FIG. 9, which is a schematic drawing illustrating a semiconductor structure including the interconnect structure according to aspects of the present disclosure. It should be noted that in FIG. 9, in each group G1, G2 and Gn, only pair of one first/second pads P1/P2 are represented, and only the functional portions of the first conductive pillars CPI and the functional portion of the second conductive pillars CP2 are shown. Further, as shown in FIG. 9, the first/second pads P1/P2 are disposed over the first layer, the second layer and the n^(th) layer. In some embodiments, the interconnect structure 100 can be coupled to two workpieces, such as a first die 110 and a second die 112, such that a semiconductor structure 10 is obtained. In another embodiments, the interconnect structure 100 can be coupled to a first package 110 and a second package 112. In other embodiments, the interconnect structure 100 can be coupled to a package, a die or a wafer having a first region 110 and a second region 112. In some embodiments, the first die, the first package or the first region 110 includes a plurality of die pads 120, and the second die, the second package or the second region 112 includes a plurality of die pads 122. In some embodiments, each of the first pads P1 is electrically connected to one of the die pads 120, and each of the second pads P2 is electrically connected to one of the die pads 122. In some embodiments, each of the first pads P1 is bonded to one of the die pads 120, and each of the second pads P2 is bonded to one of the die pads 122, such that the first die 110 and the second die 112 are bonded to the interconnect structure 100, as shown in FIG. 2. In some embodiments, the bonding of the die pads 120 and 122 to the first/second pads P1/P2 includes hybrid bonding, but the disclosure is not limited thereto. As shown in FIG. 9, by bonding the die pads 120/122 to the first/second pads PLP2, connections between the first die 110 and the second die 112 (or the first package and the second package, or the first region and second region of one wafer, one die or one package) are achieved.

Referring to FIG. 10, which is a flowchart representing a method for forming a semiconductor structure 20 according to aspects of the present disclosure. The method 20 includes a number of operations (201, 202, 203, 204, 205, and 206). The method for forming the semiconductor structure 20 will be further described according to one or more embodiments. It should be noted that the operations of the method for forming the semiconductor structure 20 may be rearranged or otherwise modified within the scope of the various aspects. It should further be noted that additional processes may be provided before, during, and after the method 20, and that some other processes may only be briefly described herein. Thus other implementations are possible within the scope of the various aspects described herein.

At operation 201, a plurality of first landing ports L1 is formed in a first region 102 a and in a second region 102 b. Also at operation 201, a first conductive line MI is formed to couple one of the first landing ports L1 in the first region 102 a to one of the first landing ports L1 in the second region 102 b. In some embodiments, a carrier (not shown) can be provided. In some embodiments, the carrier can be defined to the first region 102 a, the second region 102 b and a spacing region 104 separating the first region 102 a from the second region 102 b. A first dielectric layer (not shown) can be formed over the carrier. A plurality of first landing port L1 and at least a first conductive line M1 are simultaneously formed, as shown in FIG. 11A. In some embodiments, the first landing ports L1 are formed in the first region 102 a and the second region 102 b. The first landing ports LI in the first region 102 a can be arranged along a first direction D1 to form a plurality of rows R1, R2 and Rm, and arranged along a second direction D2 to form a plurality of columns C1, C2 and C1. The arrangement of the first landing ports LI in the first region 102 a can be designed to be similar as the first pad arrangement as mentioned above. Further, the first landing ports L1 in the first region 102 a can be grouped into a plurality of groups G1, G2 and Gn. The first landing ports L1 in the second region 102 a can be arranged along a first direction D1 to form a plurality of rows R1, R2 and Rm, and arranged along a second direction D2 to form a plurality of columns C1, C2 and Cl. The arrangement of the first landing ports L1 in the second region 102 a can be designed to be similar as the second pad arrangement as mentioned above. Further, the first landing ports L1 in the second region 102 b can be grouped into a plurality of groups G1, G2 and Gn. In some embodiments, in the first layer, each of the first landing port L1 in the first row R1 in the n^(th) group Gn in the first region 102 a is electrically connected to one of the first landing port L in the first row R1 in the first group G1 of the second region 102 b by the first conductive line M1, as shown in FIG. 11A. Additionally, the first conductive line M1 passes through the spacing region 104.

At operation 202, a first via V1 is formed on each of the first landing ports L1. Referring to FIG. 11B, in some embodiments, a plurality of first vias V1 is formed. As shown in FIG. 11B, each of the first vias V1 is formed on one of the first landing ports L.

At operation 203, a plurality of second landing ports L2 on each of the first via V in the first region 102 a and in the second region 102 b, and a second conductive line M2 is formed to couple one of the second landing ports L2 in the first region 102 a to one of the second landing ports L2 in the second region 102 b. Referring to FIG. 11C, in some embodiments, a plurality of second landing ports L2 and at least a second conductive line M2 are simultaneously formed. As shown in FIG. 11C, each of the second land ports L2 is formed one of the first vias V1. In some embodiments, in the second layer, each of the second landing port L2 in the first row R1 in the n−1^(th) group Gn−1 in the first region 102 a is electrically connected to one of the second landing port L2 in the first row R1 in the n−1^(th) group Gn−1 of the second region 102 b by the second conductive line M2, as shown in FIG. 11C. Additionally, the second conductive line M2 passes through the spacing region 104.

At operation 204, a second via V2 is formed on each of the second landing ports L2. Referring to FIG. 11D, in some embodiments, a plurality of second vias V2 is formed. As shown in FIG. 11D, each of the second vias V2 is formed on one of the second landing ports L2.

Referring to FIG. 11E, in some embodiments, operations 201 to 204 for forming the landing ports and the conductive lines, and operations for forming the via can be repeated. At operation 205, a plurality first pads P1 is formed on each of the n^(th) via Vn (i.e. the second vias V2) in the first region 102 a and a plurality of second pads P2 on each of the n^(th) vias Vn (i.e., the second vias V2) in the second region 102 b. Accordingly, an interconnect structure 100 is obtained, as shown in FIG. 11E. As mentioned above, the interconnect structure 100 includes a plurality of first pads P1 and a plurality of first conductive pillars CP1 in the first region 102 a and a plurality of second pads P2 and a plurality of second pillars CP2 in the second region 102 b. Details of the interconnect structure 100 can be similar as descriptions mentioned above, therefore those details are omitted in the interest of brevity.

Referring to FIG. 11F, at operation 202, a first die 110 is bonded to the first pads P1 in the first region 102 a and a second die 112 is bonded to the second pads P2 in the second region 102 b. As mentioned above, the first die 110 can include a plurality of first die pad 120, and the second die 112 can include a plurality of second die pads 122. As shown in FIG. 11F, each of the first die pads 120 is bonded to one of the first pads P1 in the first array A1 in the first region 102 a, and each of the second die pads 122 is bonded to one of the second pads P2 in the second array A2 in the second region 102 b. In some embodiments, the first die 110 and the second die 112 can be bonded to the interconnect structure 100 by a hybrid bonding, but the disclosure is not limited thereto. Accordingly, a semiconductor structure 10 is obtained. As shown in FIG. 11F, by bonding the die pads 120/122 to the first/second pads P/P2, connections between the first die 110 and the second die 112 are achieved.

It will be appreciated that the interconnect structure of the present disclosure includes a simple and more efficient routing design. In some embodiments, the interconnect structure may include two sets of pads: a plurality of first pads and a plurality of second pads, wherein the two sets of pads may be bonded to pads over two dies (also referred to as chips) or two packages. In some embodiments, the two sets of pads may be bonded to pads that are separated from each other, but disposed over a same wafer, a same die or a same package. In some embodiments, the first pads and the second pads are arranged to form arrays having columns and rows. In some embodiments, the rows formed by the first pads are aligned with the rows formed by the second pads. In some embodiments, the first pads may be grouped into a plurality of groups, such as a first group, a second group and an n^(th) group, arranged in columns. In some embodiments, the second pads may be grouped into a plurality of groups, such as a first group, a second group and an n^(th) group, arranged in columns. In some embodiments, the first pads and the second pads are electrically connected group-by-group. For example, the first pads and the second pads in the same group are electrically connected through conductive lines in a same layer. In some embodiments, the first pads and the second pads in the same group, including those in different rows, are electrically connected through conductive lines in the same layer. In some embodiments, the first pads and the second pads in another group are electrically connected through conductive lines in another layer. In some embodiments, the first pads and the second pads in separate groups, including those in a same row, are electrically connected through conductive lines in separate layers. Accordingly, utilization of the routing resources (the conductive lines) is improved and design for the routing resources is simplified by the provided interconnect structure.

According to one embodiment of the present disclosure, an interconnect structure is provided. The interconnect structure includes a plurality of first pads and a plurality of second pads. The first pads are arranged along a direction to form a row, and the first pads are grouped into a first group, a second group and an n^(th) group. In some embodiments, n is an integer equal to or greater than 2. The second pads are arranged along the direction to form a row parallel to the row formed by the first pads, and the second pads are grouped into a first group, a second group and an n^(th) group. The interconnect structure further includes a plurality of first conductive lines disposed in a first layer, a plurality of second conductive lines disposed in a second layer, and a plurality of n^(th) conductive lines disposed in an n^(th) layer. The first layer, the second layer and the n^(th) layer are stacked to form a multi-layered structure. In some embodiments, the first pads and the second pads are disposed over the first layer, the second layer and the n^(th) layer. In some embodiments, each of the first pads in the first group is electrically connected to one of the second pads in the first group by one of the first conductive lines in the first layer, each of the first pads in the second group is electrically connected to one of the second pads in the second group by one of the second conductive lines in the second layer, and each of the first pads in the n^(th) group is electrically connected to one of the second pads in the n^(th) group by one of the n^(th) conductive lines in the n^(th) layer.

According to one embodiment of the present disclosure, an interconnect structure is provided. The interconnect structure includes a plurality of first pads arranged to form a first array and a plurality of second pads arranged to form a second array. The first array has a first row, a second row and an m row extending along a first direction and parallel to each other along a second direction. The first pads in each of the first row, the second row and the m^(th) row are grouped into a first group, a second group and an n^(th) group extending along the second direction. In some embodiments, m is an integer greater than 2, and n is an integer equal to or greater than 2. The second array has a first row, a second row and an m^(th) row extending along the first direction and parallel to each other along the second direction. The second pads in each of the first row, the second row and the m^(th) row are grouped into a first group, a second group and an n^(th) group extending along the second direction. The interconnect structure further includes a plurality of first conductive lines disposed in a first layer, a plurality of second conductive lines disposed in a second layer and a plurality of n^(th) conductive lines disposed in an n^(th) layer. The first layer, the second layer and the n^(th) layer are stacked to form a multi-layered structure. The first pads and the second pads are disposed over the first layer, the second layer and the n^(th) layer. Each of the first pads in the first row in the first group of the first array is electrically connected to one of the second pads in the first row in the first group of the second array by one of the first conductive lines in the first layer. Each of the first pads in the second row in the first group of the first array is electrically connected to one of the second pads in the second row in the first group of the second array by one of the first conductive lines in the first layer. Each of the first pads in the m^(th) row in the first group of the first array is electrically connected to one of the second pads in the m^(th) row in the first group of the second array by one of the first conductive lines in the first layer.

According to one embodiment of the present disclosure, a method for forming a semiconductor structure is provided. The method includes following operations. A plurality of first landing ports is formed in a first region and in a second region, and a first conductive line is formed to couple one of the first landing ports in the first region to one of the first landing ports in the second region. A first via is formed on each of the first landing ports. A second landing ports is formed on each of the first vias in the first region and the second region, and a second conductive line is formed to couple one of the second landing ports in the first region and one of the second landing ports in the second region. A second via is formed on each of the second landing ports. A plurality of first pads is formed on each of the second vias in the first region, and a plurality of second pads is formed on each of the second vias in the second region. A first die is bonded to the first pads in the first region and a second die is bonded to the second pads in the second region.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. 

What is claimed is:
 1. An interconnect structure comprising: a plurality of first pads, wherein the first pads are arranged along a direction to form a row, and the first pads are grouped into a first group, a second group and an n^(th) group, and n is an integer equal to or greater than 2; a plurality of second pads, wherein the second pads are arranged along the direction to form a row parallel to the row formed by the first pads, and the second pads are grouped into a first group, a second group and an n^(th) group; and a plurality of first conductive lines disposed in a first layer, a plurality of second conductive lines disposed in a second layer and a plurality of n^(th) conductive lines disposed in an n^(th) layer, wherein the first layer, the second layer and the n^(th) layer are stacked to form a multi-layered structure, wherein the first pads and the second pads are disposed over the first layer, the second layer and the n^(th) layer, each of the first pads in the first group is electrically connected to one of the second pads in the first group by one of the first conductive lines in the first layer, each of the first pads in the second group is electrically connected to one of the second pads in the second group by one of the second conductive lines in the second layer, and each of the first pads in the n^(th) group is electrically connected to one of the second pads in the n^(th) group by one of the n^(th) conductive lines in the n^(th) layer.
 2. The interconnect structure of claim 1, wherein the first pads are separated from each other by a first distance, the second pads are separated from each other by a second distance, at least one of the first pads is adjacent to one of the second pads, and the at least one of the first pads is separated from the adjacent second pad by a third distance greater than the first distance and the second distance.
 3. The interconnect structure of claim 2, wherein a sum of widths of the first conductive lines in the first layer is less than the third distance, a sum of widths of the second conductive lines in the second layer is less than the third distance, and a sum of widths of the n^(th) conductive lines in the n^(th) layer is less than the spacing distance.
 4. The interconnect structure of claim 1, wherein the second layer is disposed over the first layer, and the n^(th) layer is disposed over an (n−1)^(th) layer.
 5. The interconnect structure of claim 1, wherein the second layer is disposed under the first layer, and the n^(th) layer is disposed under an (n−1)^(th) layer.
 6. The interconnect structure of claim 1, further comprising: a plurality of first conductive pillars electrically connecting one of the first pads in the first group to one of the first conductive lines and to one of the second pads in the first group; a plurality of second conductive pillars electrically connecting one of the first pads in the second group to one of the second conductive lines and to one of the second pads in the second group; and a plurality of n^(th) conductive pillars electrically connecting one of the first pads in the n^(th) group to one of the n^(th) conductive lines and to one of the second pads in the n^(th) group, wherein the first conductive pillars include a first functional portion, the second conductive pillars include a second functional portion, the n^(th) conductive pillars include an n^(th) functional portion, a height of the first functional portion, a height of the second functional portion and a height of the n^(th) functional portion are different from each other.
 7. The interconnect structure of claim 1, wherein at least one of the first pads comprises a subsidiary line extending along a second direction, and the second direction is different from the first direction.
 8. The interconnect structure of claim 1, wherein the first pads in each group include a first subordinate pad, a second subordinate pad and an n^(th) subordinate pad sequentially arranged along the direction, the second pads in each group include a first subordinate pad, a second subordinate pad and an n^(th) subordinate pad sequentially arranged along the direction, and the first subordinate pad of the first pads in each group is electrically connected to the first subordinate pad of the second pads in each group, the second subordinate pad of the first pads in each group is electrically connected to the second subordinate pad of the second pads in each group, and the n^(th) subordinate pad of the first pads in each group is electrically connected to the n^(th) subordinate pad of the second pads in each group.
 9. An interconnect structure comprising: a plurality of first pads arranged to form a first array, wherein the first array has a first row, a second row and an m^(th) row extending along a first direction and parallel to each other along a second direction, wherein the first pads in each of the first row, the second row and the m row are grouped into a first group, a second group and an n^(th) group extending along the second direction, m is an integer equal to or greater than 2, and n is an integer equal to or greater than 2; a plurality of second pads arranged to form a second array, wherein the second array has a first row, a second row and an m^(th) row extending along the first direction and parallel with each other along the second direction, wherein the second pads in each of the first row, the second row and the m row are grouped into a first group, a second group and an n^(th) group extending along the second direction; and a plurality of first conductive lines disposed in a first layer, a plurality of second conductive lines disposed in a second layer and a plurality of n^(th) conductive lines disposed in an n^(th) layer, wherein the first layer, the second layer and the n^(th) layer are stacked to form a multi-layered structure, wherein the first pads and the second pads are disposed over the first layer, the second layer and the n^(th) layer, each of the first pads in the first row in the first group of the first array is electrically connected to one of the second pads in the first row in the first group of the second array by one of the first conductive lines in the first layer, each of the first pads in the second row in the first group of the first array is electrically connected to one of the second pads in the second row in the first group of the second array by one of the first conductive lines in the first layer, and each of the first pads in the m^(th) row in the first group of the first array is electrically connected to one of the second pads in the m^(th) row in the first group of the second array by one of the first conductive lines in the first layer.
 10. The interconnect structure of claim 9, wherein each of the first pads in the first row in the second group of the first array is electrically connected to one of the second pads in the first row in the second group of the second array by one of the second conductive lines in the second layer, each of the first pads in the second row in the second group of the first array is electrically connected to one of the second pads in the second row in the second group of the second array by one of the second conductive lines in the second layer, and each of the first pads in the m^(th) row in the second group of the first array is electrically connected to one of the second pads in the m^(th) row in the second group of the second array by one of the second conductive lines in the second layer.
 11. The interconnect structure of claim 9, wherein each of the first pads in the first row in the n^(th) group of the first array is electrically connected to one of the second pads in the first row in the n^(th) group of the second array by one of the n^(th) conductive lines in the second layer, each of the first pads in the second row in the n^(th) group of the first array is electrically connected to one of the second pads in the second row in the n^(th) group of the second array by one of the n^(th) conductive lines in the n^(th) layer, and each of the first pads in the m^(th) row in the n^(th) group of the first array is electrically connected to one of the second pads in the m^(th) row in the n^(th) group of the second array by one of the n^(th) conductive lines in the n^(th) layer.
 12. The interconnect structure of claim 9, wherein the first pads in adjacent rows are separated from each other by a first vertical distance, the second pads in adjacent rows are separated from each other by a second vertical distance, and a sum of widths of the first conductive lines electrically connecting the first pads and the second pads in the same row is less than the first vertical distance and the second vertical distance, a sum of widths of the second conductive lines electrically connecting the first pads and the second pads in the same row is less than the first vertical distance and the second vertical distance, and a sum of widths of the n^(th) conductive lines electrically connecting the first pads and the second pads in the same row is less than the first vertical distance and the second vertical distance.
 13. The interconnect structure of claim 9, wherein at least one of the first pads is adjacent to one of the second pads, and the at least one of the first pads is separated from the adjacent second pad by a horizontal distance, wherein the sum of widths of the first conductive lines electrically connecting the first pads and the second pads in the same row is less than the horizontal distance, the sum of widths of the second conductive lines electrically connecting the first pads and the second pads in the same row is less than the horizontal distance, and the sum of widths of the n^(th) conductive lines electrically connecting the first pads and the second pads in the same row is less than the horizontal distance.
 14. The interconnect structure of claim 9, wherein the second layer is disposed over the first layer, and the n^(th) layer is disposed over an (n−1)^(th) layer.
 15. The interconnect structure of claim 9, wherein the second layer is disposed under the first layer, and the n^(th) layer is disposed under an (n−1)^(th) layer.
 16. The interconnect structure of claim 9, further comprising: a plurality of first conductive pillars electrically connecting one of the first pads in the first row in the first group of the first array to one of the first conductive lines and to one of the second pads in the first row in the first group of the second array, electrically connecting one of the first pads in the second row in the first group of the first array to one of the first conductive lines and to one of the second pads in the second row in the first group of the second array, and electrically connecting one of the first pads in the m^(th) row in the first group of the first array to one of the first conductive lines and to one of the second pads in the m^(th) row in the first group of the second array; a plurality of second conductive pillars electrically connecting one of the first pads in the first row in the second group of the first array to one of the second conductive lines and to one of the second pads in the first row in the second group of the second array, electrically connecting one of the first pads in the second row in the second group of the first array to one of the second conductive lines and to one of the second pads in the second row in the second group of the second array, and electrically connecting one of the first pads in the m^(th) row in the second group of the first array to one of the second conductive lines and to one of the second pads in the m^(th) row in the second group of the second array; and a plurality of n^(th) conductive pillars electrically connecting one of the first pads in the first row in the n^(th) group of the first array to one of the n^(th) conductive lines and to one of the second pads in the first row in the n^(th) group of the second array, electrically connecting one of the first pads in the second row in the n^(th) group of the first array to one of the n^(th) conductive lines and to one of the second pads in the second row in the n^(th) group of the second array, and electrically connecting one of the first pads in the m^(th) row in the n^(th) group of the first array to one of the n^(th) conductive lines and to one of the second pads in the m^(th) row in the n^(th) group of the second array, wherein the first conductive pillars include a first functional portion, the second conductive pillars include a second functional portion, the n^(th) conductive pillars include an n^(th) functional portion, a height of the first functional portion, a height of the second functional portion and a height of the n^(th) functional portion are different from each other.
 17. The interconnect structure of claim 9, wherein at least one of the first pads comprises a subsidiary line extending along a third direction, and the third direction is different from the first direction and the second direction.
 18. A method for forming a semiconductor structure, comprising: forming a plurality of first landing ports in a first region and in a second region and forming a first conductive line coupling one of the first landing ports in the first region to one of the first landing ports in the second region; forming a first via on each of the first landing ports; forming a second landing port on each of the first vias in the first region and the second region and forming a second conductive line coupling one of the second landing ports in the first region to one of the second landing ports in the second region; forming a second via on each of the second landing ports; forming a plurality of first pads on each of the second vias in the first region and a plurality of second pads on each of the second vias in the second region; and bonding a first die to the first pads in the first region and a second die to the second pads in the second region.
 19. The method of claim 18, wherein the first die comprises a plurality of first die pad, the second die comprise a plurality of second die pads, each of the first die pads is bonded to one of the first pads in the first region, and each of the second die pads is bonded to one of the second pads in the second region.
 20. The method of claim 18, wherein the first die and the second die are bonded to the interconnect structure by a hybrid bonding. 